Magnetic read/write heads require an electrical path between the read/write transducer and the read/write circuitry and amplifier components which are typically located at a distance from the heads or transducers. The miniaturization of disc drives in a particular head assemblies has made this task increasingly difficult. Because the signal strength is relatively low, it is important for one component to be attached to another or to the read/write circuitry with a minimum of electrical resistance between the components.
Conventionally, discrete wire assemblies have been used to make the interconnections. Manufacturing processes use manual assembly operations for ultrasonic bonding of the wires to the heads, routing, crimping, and tacking the wire assemblies down to the suspension and actuator arms, and soldering the wires to a flexible printed circuit. These manual operations are increasingly costly because of the high labor costs and also because of the difficulty in maintaining high quality. Attempts to automate ultrasonic bonding and solder termination processes have proven costly and have had only limited success. This is because the heads and wire assemblies are mounted on actuator arms which are computer controlled to rapidly move the head from position to position to read and write information on an associated computer disc. The heads must be moved as rapidly as possible over the magnetic recording medium. This rapid movement produces acceleration and deceleration forces on the heads which are very high. Moreover, the movements are repeated at a rapid rate and occur frequently over the long life of the disc. The disc drive, being frequently mounted in a portable computer, may also be subjected to other sharp shocks. Any of these shocks could break down the mechanical bond between the wires and the transducer or amplifier, breaking the connection or increasing its resistance.
Attempts to automate ultrasonic bonding and solder termination processes have been costly, and have only limited success.